Door knobs are placed on doors that open to allow humans to pass through a doorway, for example. Door knobs are also provided on doors for cabinets and drawers of a chest of drawers, for instance. In a darkened location, it would be desirable to provide light-emitting elements associated with a door knob to visually indicate the location of the door knob. It would be desirable to have the light-emitting elements function without an electrical power source, such as batteries.
The prior art generally addresses these concerns. For instance, U.S. Pat. No. 4,981,314 discloses a doorknob having various portions of an adornment on a door knob treated with a phosphorescent or luminescent material to produce a glowing effect at night or in the dark.
While the foregoing patent generally addresses the foregoing concerns, other concerns are not addressed. For instance, the light-emitting material, phosphorescent or luminescent, of the foregoing patent is exposed to the environment. Such light-emitting material is susceptible to degradation from external influences such as dirt, grime, or perspiration, for instance, from contact by a person's hand. Further, such light-emitting material is subject to wear and tear from abrasion with objects such as a person's hand or a key for a lock in, or near, the knob. Further, it may be desirable to protect one's hand from close contact with some light-emitting material, such as luminescent material energized from a radioactive salt, that could be harmful to a person.
Accordingly, it would be desirable to provide a door knob with a light-emitting location indicator that addresses the foregoing concerns.